Preheat the oven to
375°F (190°C). Carefully lift the skin up from the thigh end of each chicken leg. Divide and slide the garlic under the skin. Put the chicken skin back to its original position. Place the chicken, skin-side-up, in a large roasting pan. Brush with the olive oil, and then sprinkle with the herbs, salt and pepper. Roast 45-50 minutes, or until the chicken is cooked through. Set the chicken on a platter and keep warm in the oven. Remove the fat from the pan-drippings and then place the pan on the stove. Add the stock/flour mixture and bring to a boil. Whisk and simmer until thickened, and then season to taste. Serve the chicken with the gravy in a sauceboat alongside.